A NAND flash memory is known as a kind of semiconductor memory device. A NAND flash memory comprising three-dimensionally stacked memory cell transistors is also known.
A NAND flash memory comprises NAND strings, and each of the NAND strings comprises memory cell transistors and a select transistor that are serially connected. A word line is connected to a gate of the memory cell transistor, and a select gate line is connected to a gate of the select transistor. When resistance of the select gate line is high, potential of the select gate line floats up due to capacitive coupling with a word line adjacent to the select gate line, during a potential variation of the adjacent word line. Thus, the select transistor can not be normally cut off, and a leak current is generated from a channel of a boosted NAND string. As a result, erroneous writing occurs.